Input from a text file to get a char C++ - c++

I am having trouble with getting input after a modifier in the text of a .txt file.
What I want to do is if the .txt file has the word "type:" then anything after that will be put into a char.
My code so far:
#include "stdafx.h"
#include <windows.h>
#include "VKH.h"
#include "Strmif.h"
#include <iostream>
#include <stdio.h>
#include <string>
#include <fstream>
void GetDocumentandRead() {
string line;
ifstream myfile (line1);
if (myfile.is_open())
{
while ( !myfile.eof() )
{
getline (myfile,line);
char aline[100];
strcpy(aline, line.c_str());
printf(aline, "\n");
if (line.compare("mouseup") == 0){
MouseUp(10);
}
if (line.compare("mousedown") == 0){
MouseDown(10);
}
if (line.compare("mouseright") == 0){
MouseRight(10);
}
if (line.compare("mouseleft") == 0){
MouseLeft(10);
}
if (line.compare("mouseclick") == 0){
MouseClick();
}
if (line.compare("enter") == 0){
Enter();
}
if (line.compare("ctrltab") == 0){
CtrlTab();
}
if (line.compare("tab") == 0){
Tab();
}
if (line.compare("altf4") == 0){
AltF4(0);
}
if (line.compare("alttab") == 0){
AltTab();
}
if (line.compare("mousecenter") == 0){
MouseCenter();
}
if (line.compare(6,5,"type:") == 0){
//Don't know what to put here...
}
}
myfile.close();
}
else printf("\nUnable to open file\n\n");
}
So after the "type:" in a text file it would type that using a function I have called TypeStr();
void TypeStr(char *lpszString)
{
char cChar;
while((cChar=*lpszString++)) // loops through chars
{
short vk=VkKeyScan(cChar); // keycode of char
if((vk>>8)&1){keybd_event(VK_LSHIFT,0,0,0);} // hold shift if necessary
keybd_event((unsigned char)vk,0,0,0); // key in
keybd_event((unsigned char)vk,0,KEYEVENTF_KEYUP,0); // key out
if((vk>>8)&1){keybd_event(VK_LSHIFT,0,KEYEVENTF_KEYUP,0);} // release shift if necessary
}
}
Any help would be appreciated. Thanks!

First you should rewrite your TypeStr function so that it takes a const char *. Like this
void TypeStr(const char *lpszString)
{
...
}
no other changes needed.
Then you should call that function from your code like this
if (line.compare(6,5,"type:") == 0){
TypeStr(line.c_str() + 11);
}
The reason that you have to change your TypeStr function to const char* (apart from it being general good style) is that the c_str() method of std::string returns a const char* not a char*.

Related

Constructor not working as intended

I am trying to get this constructor to do these set of things:
This constructor tries to open the file whose name is passed
to it in filename. If file opens successfully, calls function
getFileSize to determine how many bytes should be allocated
for the message. Allocates space for message and reads the
content from the file into it. Closes the file at the end.
Member variable length should be set to the file size.
If file cannot be found, length should be set to zero.
I am having trouble currently, when I try to run my program I get an error as it is not even reading my file and having trouble not understanding the problem. Any help would be appreciated thanks.
Constructor:
Message::Message(std::string filename) {
fstream fin(filename);
if (fin.fail())
{
cout << "failed";
}
else {
length = getFileSize(fin);
message = new char[length];
fin.getline(message, length); {
fin >> message;
}
}
fin.close();
}
.h File:
#ifndef MESSAGE_H_
#define MESSAGE_H_
#include <fstream>
#include <string>
#include <cstring>
#include <cstdlib>
#include <iostream>
class Message
{
private:
char *message; // holds the message
int length; // holds the the message length
static const short ALPHABET_SIZE = 26;
char code[ALPHABET_SIZE]; // holds the cypher alphabet
// iztohndbeqrkglmacsvwfuypjx
// ex: an 'a' in the original message should be converted to 'i', 'b' should be converted to 'z' and so forth
// returns the input file size in bytes
std::streamsize getFileSize(std::fstream &file) const
{
std::streamsize fsize = 0;
file.seekg(0, std::ios::end);
fsize = file.tellg();
file.seekg(0, std::ios::beg); // moves file pointer back to the beginning
return fsize;
}
public:
Message(std::string filename);
// The destructor frees the space allocated to message
virtual ~Message();
// Decodes the message
void decode();
// Capitalizes first letter in each sentence
void fixCapitalization();
// Prints the content of message on the screen
void dump() const;
// Returns true if the message is empty
bool isEmpty() const;
};
Here are my files:
OBJECT.CPP:
#include "Message.h"
using namespace std;
Message::Message(std::string filename) {
fstream fin(filename);
if (fin.fail())
{
cout << "failed";
}
else {
length = getFileSize(fin);
message = new char[length];
fin.getline(message, length); {
fin >> message;
}
}
fin.close();
}
Message::~Message()
{
//dtor
}
void Message::decode() {
int offset;
strcpy(code, "iztohndbeqrkglmacsvwfuypjx");
for (int i = 0; i < strlen(message); i++) {
if (message[i] == ' ') continue;
if (message[i] == ',') continue;
if (message[i] == '.') continue;
offset = int(message[i] - 'a');
message[i] = code[offset];
}
}
void Message::fixCapitalization() {
for (int i = 0; i < strlen(message); i++) {
if (message[0] != ' ' || message[0] != ',') {
message[0] = toupper(message[0]);
}
if (message[i] == '.' || message[i] == '?' || message[i] == ',') {
message[i + 2] = toupper(message[i + 2]);
}
}
}
void Message::dump() const {
for (int i = 0; i < strlen(message); i++) {
cout << message[i];
}
}
bool Message::isEmpty() const {
if (length == 0) {
return true;
}
else {
return false;
}
}
.H file:
/*
* Message.h
*
* Created on: Dec 11, 2016
* Author: hellenpacheco
*/
#ifndef MESSAGE_H_
#define MESSAGE_H_
#include <fstream>
#include <string>
#include <cstring>
#include <cstdlib>
#include <iostream>
class Message
{
private:
char *message; // holds the message
int length; // holds the the message length
static const short ALPHABET_SIZE = 26;
char code[ALPHABET_SIZE]; // holds the cypher alphabet
// iztohndbeqrkglmacsvwfuypjx
// ex: an 'a' in the original message should be converted to 'i', 'b' should be converted to 'z' and so forth
// returns the input file size in bytes
std::streamsize getFileSize(std::fstream &file) const
{
std::streamsize fsize = 0;
file.seekg(0, std::ios::end);
fsize = file.tellg();
file.seekg(0, std::ios::beg); // moves file pointer back to the beginning
return fsize;
}
public:
/*
* This constructor tries to open the file whose name is passed
* to it in filename. If file opens successfully, calls function
* getFileSize to determine how many bytes should be allocated
* for the message. Allocates space for message and reads the
* content from the file into it. Closes the file at the end.
* Member variable length should be set to the file size.
* If file cannot be found, length should be set to zero.
*/
Message(std::string filename);
// The destructor frees the space allocated to message
virtual ~Message();
// Decodes the message
void decode();
// Capitalizes first letter in each sentence
void fixCapitalization();
// Prints the content of message on the screen
void dump() const;
// Returns true if the message is empty
bool isEmpty() const;
};
#endif /* MESSAGE_H_ */
MAIN.CPP:
#include <iostream>
#include <stdlib.h>
#include <fstream>
#include "Message.h"
using namespace std;
int main()
{
// create a message object with the content of Encrypted.txt
Message m("Encrypted.txt");
if (m.isEmpty())
{
cout << "Could not read message";
return EXIT_FAILURE;
}
cout << "Original message: " << std::endl;
m.dump();
cout << std::endl << std::endl;
m.decode();
m.fixCapitalization();
cout << "Decoded message: " << std::endl;
m.dump();
cout << std::endl << std::endl;
return EXIT_SUCCESS;
}
The following file is the .txt file I am trying to open and "decode" and is all on 1 line:
ifqkwxcadf ar cei fpoi masif cd cei xkdqirr du pxxnwafm pf pnmdkaceo cd p oirrpmi, teaqe rqkpohnir cei gpcp af ac-oplafm ac sikw gauuaqvnc pfg caoi qdfrvoafm, au fdc xkpqcaqpnnw aoxdrrahni, cd gigvqi cei dkamafpn masif dfnw cei ifqdgig gpcp. afxvcr cd cei pnmdkaceo cwxaqpnnw afsdnsi pggacadfpn riqkic gpcp qpnnig liwr, teaqe xkisifcr cei oirrpmi ukdo hiafm giqdgig-isif au cei pnmdkaceo ar xvhnaqnw lfdtf.
Problems with
message = new char[length];
fin.getline (message, length); {
fin >> message;
}
getline will stop if a newline character is encountered.
The fin >> message; line will overwrite what was read in getline.
The { and } don't make sense at all. They are not problems per se but they lead me to think that you are not clear on what you are trying to do.
I would change those lines to
message = new char[length + 1]; // Add an extra character if
// message is supposed to be null
// terminated.
fine.read(message, length);
message[length] = '\0';

Execlp() not taking parameter list, just the command. UNIX/LINUX programming

I am trying to create a microshell. It reads commands in, parses this and splits this, then executes. To parse, first I separate by the delimiter || to get up to two commands if there is a pipe. The split each command into an array of strings.
I thought this is how execlp works, but it only runs the command even though the C string "cmd1" does contain the arguments. Can someone please help me understand how I am passing the parameters wrong to the execlp function?
shell.h
/****************************************************************
PROGRAM: MicroShell(assignment 4)
FILE: shell.h
AUTHOR: Nick Schuck
FUNCTION: This contains the header for the shell class
****************************************************************/
#ifndef _shell_h
#define _shell_h
#include <sys/types.h>
#include <unistd.h>
#include <cstdio>
#include <pwd.h>
#include <cstring>
#include <sys/wait.h>
#include <cstdlib>
#include <vector>
class Shell
{
private:
char buffer[1024];
const char *cmd1[10];
const char *cmd2[10];
public:
Shell(); //default constructor
void askForCommand();
void readCommandLine();
void parseBuffer();
void invokeCommand();
void executeOneCommand();
void executeTwoCommands();
};
#endif
shell.cc
/***************************************************************
PROGRAM: MicroShell(assignment 4)
FILE: shell.c
AUTHOR: Nick Schuck
FUNCTION: This file contains the implementation of
class shell from file "shell.h"
****************************************************************/
#include "shell.h"
#include <iostream>
Shell::Shell()
{
/**Get current user*/
struct passwd *p = getpwuid(getuid());
if (!p) //Error handling
puts("Welcome to Nick Schuck's MicroShell, Anonymous");
/**Welcome message for my shell*/
printf("\n\nWelcome to Nick Schuck's Microshell, user %s!\n\n", p->pw_name);
}
void Shell::askForCommand()
{
/**Command Prompt*/
printf("myshell>");
}
void Shell::readCommandLine()
{
/**Read stdin into buffer array IF no*/
/**errors occur */
if (fgets(this->buffer, 1024, stdin) != NULL)
{
this->buffer[strlen(this->buffer) - 1] = 0;
}
}
void Shell::parseBuffer()
{
/**Variables*/
int i = 0, u = 0,
t = 0;
char *ptr;
char parsingBuffer[2][512];
/**Parse buffer for multiple commands*/
strcpy(parsingBuffer[0], strtok(this->buffer, "||"));
while ((ptr = strtok(NULL, "||")) != NULL)
{
i++;
strcpy(parsingBuffer[i], ptr);
}
//**Get first command*/
this->cmd1[0] = strtok(parsingBuffer[0], " ");
while ((ptr = strtok(NULL, " ")) != NULL)
{
u++;
this->cmd1[u] = ptr;
this->cmd1[u+1] = '\0';
}
//!!!TESTING TO SEE COMMAND ARE IN CMD1
int b = 0;
while(cmd1[b] != '\0')
{
std::cout << cmd1[b] << "\n";
b++;
}
/**Get second command*/
this->cmd2[0] = strtok(parsingBuffer[1], " ");
while ((ptr = strtok(NULL, " ")) != NULL)
{
t++;
this->cmd2[t] = ptr;
}
}
void Shell::invokeCommand()
{
if (this->cmd1[0] == NULL)
{
//do nothing
}
else if(this->cmd1[0] != NULL && this->cmd2[0] == NULL)
{
executeOneCommand();
}
else if(this->cmd1[0] != NULL && cmd2[0] !=NULL)
{
executeTwoCommands();
}
}
void Shell::executeOneCommand()
{
pid_t pid; //pid for fork
int status;
char args[512];
if ((pid = fork()) < 0)
{
printf("fork error\n");
exit(-1);
}
else if(pid == 0) //Child Process
{
execlp(cmd1[0], *cmd1);
}
else //Parent Process
{
if ((pid = waitpid(pid, &status, 0)) < 0)
{
printf("waitpid error in main\n");
exit(-1);
}
}
}
main.cc
#include "shell.h"
#include <iostream>
#include <vector>
int main()
{
const int BUFFER_SIZE = 1024;
const int MAX_COMMANDS_IN_BUFFER = 2;
/**Initialize a new shell object*/
Shell shell;
/**Print command prompt to screen*/
shell.askForCommand();
/**Read users command*/
shell.readCommandLine();
/**parse buffer to find individual*/
/**commands */
shell.parseBuffer();
/**Invoke command*/
shell.invokeCommand();
}
You can't use execlp() — you must use execvp().
execvp(cmd1[0], cmd1);
To use execlp(), you must know at compile time the fixed list of arguments for the command — you must be able to write:
execlp(cmd_name, arg0, arg1, …, argN, (char *)0);
Your call to execlp() is also faulty because you don't provide the (char *)0 argument to indicate the end of the argument list.
Your code also needs to handle exec*() returning, which means the command failed. Usually that means it should print an error message (that the command was not found, or permission denied, or whatever), and then exit with an appropriate non-zero error status.

C++ SetConsoleTextAttribute changing char in a string

I have a C++ string which contains some characters. How can I change the char colour if I meet certain chars? Below is the sample code:
#include <iostream>
#include "windows.h"
using namespace std;
int main()
{
HANDLE h;
h = GetStdHandle(STD_OUTPUT_HANDLE);
string str = "my name is meow.";
for(int i=0; i<str.length(); i++)
{
if(str[i] == 'm')
{
//change the char 'm' to red color..
}
cout<<str[i];
}
return 0;
}
if(str[i] == 'm')
{
SetConsoleTextAttribute(h, FOREGROUND_RED);
cout<<str[i];
}
else
{
SetConsoleTextAttribute(h, 15);
cout<<str[i];
}
maybe this is what you wanna do?

Child doesn't terminate correctly in fork

I am writing a c program for a class that is a small shell. The user inputs a command, and the code executes it using the exec() function.
I need to have a fork in the process so all the work is done in the child process. The only problem is that the child won't terminate properly and execute the command. When I run the code without the fork, it executes commands perfectly.
The problem seems to be coming from where I am creating the string to be used in the execv call. It's the line of code where I call strcpy. If I comment that out, things work fine. I also tried changing it to strncat with the same problem. I'm clueless as to what's causing this and welcome any help.
#include <sys/wait.h>
#include <vector>
#include <sstream>
#include <cstdlib>
#include <stdio.h>
#include <iostream>
#include <string.h>
#include <unistd.h>
using namespace std;
string *tokenize(string line);
void setCommand(string *ary);
string command;
static int argument_length;
int main() {
string argument;
cout << "Please enter a unix command:\n";
getline(cin, argument);
string *ary = tokenize(argument);
//begin fork process
pid_t pID = fork();
if (pID == 0) { // child
setCommand(ary);
char *full_command[argument_length];
for (int i = 0; i <= argument_length; i++) {
if (i == 0) {
full_command[i] = (char *) command.c_str();
// cout<<"full_command " <<i << " = "<<full_command[i]<<endl;
} else if (i == argument_length) {
full_command[i] = (char *) 0;
} else {
full_command[i] = (char *) ary[i].c_str();
// cout<<"full_command " <<i << " = "<<full_command[i]<<endl;
}
}
char* arg1;
const char *tmpStr=command.c_str();
strcpy(arg1, tmpStr);
execv((const char*) arg1, full_command);
cout<<"I'm the child"<<endl;
} else if (pID < 0) { //error
cout<<"Could not fork"<<endl;
} else { //Parent
int childExitStatus;
pid_t wpID = waitpid(pID, &childExitStatus, WCONTINUED);
cout<<"wPID = "<< wpID<<endl;
if(WIFEXITED(childExitStatus))
cout<<"Completed "<<ary[0]<<endl;
else
cout<<"Could not terminate child properly."<<WEXITSTATUS(childExitStatus)<<endl;
}
// cout<<"Command = "<<command<<endl;
return 0;
}
string *tokenize(string line) //splits lines of text into seperate words
{
int counter = 0;
string tmp = "";
istringstream first_ss(line, istringstream::in);
istringstream second_ss(line, istringstream::in);
while (first_ss >> tmp) {
counter++;
}
argument_length = counter;
string *ary = new string[counter];
int i = 0;
while (second_ss >> tmp) {
ary[i] = tmp;
i++;
}
return ary;
}
void setCommand(string *ary) {
command = "/bin/" + ary[0];
// codeblock paste stops here
You said:
Its the line of code where I call
strcpy.
You haven't allocated any memory to store your string. The first parameter to strcpy is the destination pointer, and you're using an uninitialized value for that pointer. From the strcpy man page:
char *strcpy(char *s1, const char *s2);
The stpcpy() and strcpy() functions copy the string s2 to s1 (including
the terminating `\0' character).
There may be other issues, but this is the first thing I picked up on.

Outputting from file one line at a time

I'm trying to output text from a file one line at a time. I'm currently hardcoding it and I have this so far:
int main(int argc, char *argv[])
{
int x;
int k;
int limit = 5;
FILE *file;
file = fopen("C:\\Documents and Settings\\jon\\My Documents\\Visual Studio 2008\\Projects\\Project1\\Assignment8_2\\Debug\\TestFile1.txt", "r");
if (file == NULL) {
perror("Error");
}
for (k = 1; k <= limit; k++) {
while ((x = fgetc(file)) != '\n') {
printf("%c", x);
}
}
fclose(file);
}
I was wondering where in the code above, if at all, I can check for EOF. I assume I need to do that, but not sure why. Still learning.... Thanks!
If you can bound the maximum length of a line, fgets may be a better way to read each line; but since you mention C++, you might consider using, instead, getline (caveat: fgets also put the \n in the buffer it fills, getline doesn't). Both make easy to check for end of file (fgets returns NULL on eof, getline sets the eofbit on its istream argument, which it also returns).
Maybe you can try this:
#include <iostream>
#include <iomanip>
#include <fstream>
using namespace std;
int main() {
int sum = 0;
int x;
ifstream inFile;
inFile.open("test.txt");
if (!inFile) {
cout << "Unable to open file";
exit(1); // terminate with error
}
while (inFile >> x) {
sum = sum + x;
}
inFile.close();
cout << "Sum = " << sum << endl;
return 0;
}
fgets() for C, getline() for C++.
C:
#include <stdio.h>
#include <stdlib.h>
// adjust as appropriate
size_t const MAX_LINE_LENGTH = 1024;
int main()
{
FILE * in;
char line[ MAX_LINE_LENGTH ];
if ( ( in = fopen( "test.txt", "r" ) ) == NULL )
{
puts( "Failed to open test.txt." );
return EXIT_FAILURE;
}
while ( fgets( line, MAX_LINE_LENGTH, in ) != NULL )
{
printf( "%s", line );
}
fclose( in );
return EXIT_SUCCESS;
}
C++:
#include <iostream>
#include <fstream>
#include <string>
int main()
{
std::ifstream in( "test.txt" );
std::string line;
while ( getline( in, line ) )
{
std::cout << line << std::endl;
}
in.close();
return 0;
}
you can call feof() to check for EOF or check if the return code for fgetc() matches EOF.
I'm adding both versions to your code although I'm not sure what the loops (especially the outer one) are supposed to do, but within the context of your sample, EOF checking would look like this..
/* EOF would now terminate both loops, using feof() and fgetc() return to check EOF */
for (k = 1; k <= limit && !feof(file); k++) {
while ((x = fgetc(file))!='\n' && x!=EOF) {
printf("%c", x);
}
}
you should check the eof from the output of fgetc:
...
x = fgetc(file);
while (x != '\n' && x != EOF) {
...
fgetc manual there